Disconnectable rigid connection of mounting parts especially furniture walls

ABSTRACT

Improved connection between two mounting parts. There is used at least one connecting element attached to one of the mounting parts which has a pin protruding into a bore of the other mounting part and thereby taking up the shear forces while additional tensioning means, acting in direction of the bore are provided to tighten both mounting parts against each other.

United States Patent Wippermann DISCONNECTABLE RIGID CONNECTION OFMOUNTING PARTS ESPECIALLY FURNITURE WALLS [72] Inventor: JosefWippermann, Paderbom, Germany [73] Assignee: Richard Heinze,Herford/Westphalia, Germany [22] Filed: Jan. 29, 1970 [21] Appl. N0.:6,684

[30] Foreign Application Priority Data June 11, 1969 Germany ..P 19 29685.6

[52] U.S. Cl. 287/2092 F, 85/83, 151/41.73 [51] Int. Cl ..Fl6b 12/14[58] Field of Search ..287/20.92 F, 20.92 E, 20.92 K; 85/82, 83, 72, 39,4, 84; 15l/41.73

[56] References Cited UNITED STATES PATENTS 363,074 5/1887 Lockwood..85/4 UX 1,182,015 5/1916 Kennedy ..85/72 1,476,501 12/1923 Ferry..287/20.92 E

[ 1 Oct. 3, 1972 2,630,857 3/ 1953 Cohen ..287/20.92 E X 2,677,1605/1954 Peterson ..287/20.92 E X 3,312,139 4/1967DiChristina.....287/20.92 E X 3,339,953 9/1967 Bohn ..85/4 X 3,421,5641/1969 Neuschotz ..15l/41.76 X 3,424,051 1/1969 Baugh ..85/55 X3,462,114 8/1969 ODell et a1 ..85/4 UX 3,504,723 4/1970 Cushman et a1....151/41.76 X

FOREIGN PATENTS OR APPLICATIONS 449,331 4/1968 Switzerland ..15l/41.73

Primary Examiner-David J. Williamowsky Assistant Examiner-Wayne L. SheddAtt0rneySparrow and Sparrow [5 7] ABSTRACT Improved connection betweentwo mounting parts. There is used at least one connecting elementattached to one of the mounting parts which has a pin protruding into abore of the other mounting part and thereby taking up the shear forceswhile additional tensioning means, acting in direction of the bore areprovided to tighten both mounting parts against each other.

11 Claims, 40 Drawing Figures PAIENTEnnm Ian 3.595.555

SHEET 3 OF 4 I DISCONNECTABLE RIGID CONNECTION OF MOUNTING PARTSESPECIALLY FURNITURE WALLS BACKGROUND OF THE INVENTION In many technicalfields especially in the production of furniture there exists theproblem of connecting rigidly two disconnectable construction parts in asimple but safe manner. For this it is important to compensate possiblyexisting shear forces between the connected parts.

SUMMARY According to the invention this problem of connecting rigidlybut disconnectably two mounting parts is solved by using at least oneconnecting element attached to one of the mounting parts and protrudinginto a bore of the other mounting part and thereby taking up the shearforces while additional tensioning means, acting in the axial directionof the bore are provided to tighten both mounting parts against eachother. The pin itself may be shaped as a tightening screw. By thisconstruction a rigid mounting connection of parts is attained which isconsiderably superior in strength to conventionally known connections.

Various further and more specific purposes, features and advantages willclearly appear from the detailed description given below taken inconnection with the accompanying drawings which form part of thisspecification and illustrate merely by way of examples embodiments ofthe device of the invention.

BRIEF DESCRIPTION OF DRAWING In the following description and in theclaims, parts will be identified by specific names for convenience, butsuch names are intended to be as generic in their application to similarparts as the art will permit. Like reference characters denote likeparts in the several figures of the drawings, in which FIG. 1 is asection of a connection between two central walls, or adjacent walls ofside by side arranged furniture pieces,

FIG. 2 is a section of a corner connection of two furniture walls,

FIGS. 3 and 4 show side and front views of a hollow insert,

FIG. 4a shows the front view of a chain of connecting shear plugs ordowel pins,

FIG. 5 is a section through a modified form of comer connection, usablealso as an intermediate shelf connection,

FIG. 5a is a modification of FIG. 5,

FIG. 5b is a further modification of FIG. 5,

FIGS. 6 and 7 show a plan view and a side view, respectively, of aconnecting piece in the construction of FIG. 5,

FIG. 8 shows a side view of a connecting piece similar to the one seenin FIG. 7 with separate dowel pins,

FIG. 9 shows a front view of a connecting piece according to FIG. 8,

FIG. 10 is a cover cap for tightening screws according to FIG. 2 and 5,

FIG. 11 is a cover cap of modified construction in view of FIG. 10,

FIGS. 12 and 13 is a modified connecting block in a vertical andhorizontal cross-section, respectfully, of the furniture,

FIGS. 13' to 13" are modifications of FIG. 12 and 13,

FIG. 14 is a chain of connecting pieces according to FIG. 12 and 13 heldtogether by narrow necks FIGS. 15 to 18 are connecting pieces similar toFIG. 5 to 7 in longitudinal section, plan and side views and incross-section along the line XVIII XVIII of FIG. 15, respectively I FIG.19 to 22 show views and sections of a further embodiment of theinvention,

FIG. 23 is a plan view of the bore in the furniture bottom for insertinga connecting piece according to FIGS. 5, 5a, 5b, 6 to 9, 12, 15 to 22,

FIG. 24 is a modification of FIG. 23,

FIGS. 25 to 34 is a connecting piece with a locking catch and a pushbutton.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, the numbers 1 and 2designate two furniture walls, that is, adjacent sidewalls of twoclosely positioned furniture pieces, joined together by a socket-likeconnecting plug 3. The latter, is held on the furniture wall 2 with itsenlarged end and the threaded hole thereof is engaged by a screw 5,passing wall 1. The length of socket 3 is greater than the thickness ofwall 2, so that the shear forces between both furniture pieces areabsorbed by plug'3. The latter and screw 5 may be provided on theirenlarged top ends with bores 6 and 7, respectively which may receive acap 9 having a pin. The cap maybe made of plastics having the color ofthe furniture in order to obtain a goodlooking surface. The embodimentshown in FIGS. 2 to 4 is concerns a corner connection. A plug 10 isinserted into a blind hole 11 of a cover or bottom plate 12 of afurniture piece, so that only a cylindrical hollow pin 13 projects fromthe front face of plate 12. Pin 13 fits into a corresponding bore 13' ofthe side wall 14, into which from the outside a wood screw 15 isinserted engaging the bore 10'. Pin 13 is also absorbing the shearforces in this case, while the wood screw 15, which may be also coveredby a cap 9, tightens firmly to the parts 12 and 14. The cross-section ofthe plug 10, as it may be seen from FIG. 4 and 4a, is preferably oval,and the plug so inserted in the bore in such manner that the largerdiameter is parallel to the wall surface, thereby preventing a burstingof the wood of the wall. A longitudinal groove 16 serves as a gluegroove. All countersunk heads of the screws'S, 15 or plugs 3 preferablynot only are provided with a head bore 6 for the cap 9 but also with ascrewdriver slot 6. Furthermore, the screws have a thin cylindrical coreand thin thread flanges like screws for boards pressed of woodchips. Asit may be seen from FIG. 4a, plugs 10 (made of plastics), are kepttogether by little bridges 17 before being inserted which are formed bythe same material as the plugs during the production thereof, and aresimply sheared ofi like a wire stitch of a stitching machine by adriving-in-instrument.

The bridge connection of plugs 10 makes it possible to keep the correctdirection, so that the oval is always in the proper position relative tothe wall. A metal thread screw may be also used instead of a wood screw15, if the plug has a correspondingly prepared bore 10'.

A modified construction piece is shown in FIG. 5 to 7. It is especiallyuseful, when the connecting piece has to carry heavier loads, forexample, of a cupboard shelf. In this embodiment the connecting piece isa block 18 of a larger diameter on which a cylindrical stud 19 of asmaller diameter with an inner bore 19 is moulded in one piece. Stub 19projects into a bore 20 of the side wall 14 and holds a screw 15 as inthe example shown in FIGS. 2 to 4. Block 18 projects into a bore 18 inthe underside of plate 12 and has a plate-like flange 21 at its end,against which the supporting plate 12 can abut. Flange 21 abuts closelyto the sidewall 14, and the three parts 18, 19, 21 are connected by aridge 22, which increases the stability. It is advantageous to increasethe height of the ridge in the direction towards the pin having thesmaller diameter by a small slope of 3 degrees in order to simplify theassembly of the mounting parts, whereby the ridge may be moved by thetightening screw after the assembly the pin abuts against the adjacentmounting part. At the assembly, the block 18 is first put with itsextension 19 into bore 20 of the side wall 14. Thereafter the bottom orthe supporting plate 12, which has corresponding recesses 18', 18" or44, 45 (FIG. 23), is slid on block 18.

Thereafter, the screw 15 is inserted which will hold, the parts 12 and14 rigidly together after final tighten-v Numeral 14 may designate acenter wall. As may be seen in FIG. 5, the studs of two blocks 18 may beinserted from both sides into a bore 14. One of the studs 19 has awoodscrew 15' without a head, on which the other stud 19 may be screwed,until both blocks 18 abut the wall 14 in the proper position,

As it is shown in FIGS. 5a and 5b, the blocks may be also held by aninserted wood screw 15", wherein,.as shown in FIG. 5b, the stud 19" maybe a slotted expanding dowel provided with barbs 19".

In the modification of FIGS. 8 and 9 the projection 23 with the smallerdiameter on block 18 reaches only up to the surface of wall 14, whilepart 14, positioned in wall 24 is formed as a separate barb-dowel.Conveniently it is inserted in the wall before mounting and fortightening it is engaged by a screw, for example by a metal screw 25passing through block 18.

In FIG. 10 a cover cap 9 is shown with a feathered sharp edge 28.

Another modified cover cap is shown in FIG. 11 for the case that thecountersunk screw is inserted in a counterbored bore 29 of wall 14; thenthe pin 30 of cap 9 fills theentire bore 29.

The connecting block 31 shown in FIGS. 12, 13 having a central bore 31'is inserted into a wall 12 at a certain distance from an adjacent wall14 and either a selfthreading stud or a metal screw 32 is inserted intocentral bore 31 passing through wall 14. Block 31 serves in this case totransmit the large forces of screw 32 to a more extended surface of thewall 12. Block 31 itself which may consist of tough plastics is able towithstand these forces without damage. In this embodiment an extremelyrigid connection is obtained by large force that is by approximately 200kg tension force, whereby the tightly fitted screw bolt 32 takes theshear force. A

screwdriver slot 31" arranged parallel to bore 31 pro-.

vides a good orientation.

Blocks shown in FIGS. 6 to 9, 12 and 13 by connecting portions into achain of correctly aligned pieces (FIG. 14) fromwhich they may beseparated piece by piece at assembly by a driving-in tool. In case ofFIGS. 12, 13 the alignment screwdriver slot 31" may be omitted andaccording to FIG. 13' to 13" a bore 31 may be provided for receiving thepin of a cap 9.

The construction shown to FIG. 15 to 18 is similar to the one of FIGS. 5to 7. A block 18 is provided with a flange plate 21 and with aprojection 19. Parts 18, 19,

21 maybe also connected with one another by an intermediate portion 22similar to FIG. 5. The projection 19 has one or more ribs 34 on theoutside thereof in order to hold it in place in the wall and forcompensating of manufacturing tolerances. A bore 35 is provided with arib 36 for receiving a tightening screw 15 in order to insert thetightening screw loosely and prevent it from dropping out. Tighteningscrew 15 shown in dotted lines in FIGS. 15 and 19 may have a head 42positioned in a recess 37 to avoid protruding parts of metal.

A similar construction is shown in FIG. 19 to 22 in which projection 19a reduction 39 of the bore 35 so that the tightening screw will causeprojection. 19 to expand and to burst. Furthermore the projection 19 hasradial recesses 40 and 41 closely reaching to reduction 39. Whentightening screw 42 is inserted the thin parts 43 of the wall with crackwithout losing their contact surface with the tightening screw andwithout loss of locking force. When the screw is removed the crackspractically close to their original form.

In FIGS. 23 and 24 examples are shown as to how the furniture wall partscan be prepared for receiving the connecting elements 18. In theembodiment shown in FIG. 23 the bore 44 serves for receiving the block18 with the larger diameter while by the smaller bore 45 so muchmaterial is removed that intermediate position 22 with projection 19fits in the remaining opening. In the embodiment shown in FIG. 24 theconditions are selected such that only a single bore 44 for the largerdiameter of block 19 is needed while by the close proximity of this boreto the wall surface the remaining wall part 46, can be simply brokenaway so that a double boring process is avoided.

The embodiment shown in FIG. 25 to 34 is a disconnectable connectionreleasable by a push button for furniture, doors, traps, convertiblebeds or the like and particularly suitable for sliding and foldingtables.

The cup shaped body 47 (FIG. 25) made of plastics having on the outsideribs 48 for preventing rotation can be driven into a bore 49. By a dropof glue a good hold is guaranted.

The locking pin 50 (FIG. 27) hasa threaded part 51 and is screwed into aplug 52 (FIG. 26). By a driving-in tool (not shown) locking pin 50together with plug 52 can be inserted to the exact depth into a bore 53(FIG. 32) so that an adjustment is not needed. When the lock is closed,pin 50 enters with its cone-shaped point54 the hole 55 of the closingplate 56 (FIG. 29). A helical spring 57 (FIG. 30) holds plate 56 inexact alignment (FIG. 29) for safe locking. A socket 58 (FIG. 31) ofplastics having serrations 59 is used-for better guiding of locking pin50'into plug 47 and can be driven in at the same level as plug 52 intothe counterpart 12. By

operating the push button 60 (FIG. 28) at the head of cup-shaped body 47(FIG. closing plate 56 (FIG. 29) is pushed out of the groove 61 oflocking pin 50 (FIGS. 26 to 27) and is thereby unlocked. Closing plate56 tilts by the pushing and is guided thereafter by the projection 62 inthe rectangular recess 63 of cup 47.

FIG. 33 shows an application of the invention on a sliding table, FIG.34 an application of the invention on a folding table a folding table.

What I claim is:

l. Fastening systsm for connecting two adjacent plate-like parts,particularly for connecting two walls of furniture, said parts beingdisposed perpendicularly to each other, said system comprising acylindrical block member, said member being positioned in a first borehold in the underside of the first one of said plate-like parts, theaxis of said cylindrical block member being perpendicular to the surfaceof said underside of said plate-like first part, a screw memberanchoring said cylindrical block member in the second one of saidplate-like parts, a cylindrical stud disposed perpendicular to said axisof said cylindrical block member, said stud integrally formed with saidcylindrical block member, said stud at least partly embracing said screwmember and engaging a second bore hole in said second part, the diameterof said second bore hole being equal to the diameter of said stud, alaterally projecting plate-like flange on one side of said cylindricalblock member, said plate-like flange on one side of said cylindricalblock member, said plate-like flange abutting against said surface ofsaid underside of said plate-like first part in the area surroundingsaid first bore hole in said underside of said plate-like part andabutting against the surface of said plate-like second part.

2. Fastening system according to claim 1, said stud having a lengthsubstantially shorter than the thickness of said second plate-like part,and said screw going through said second plate-like part, said screwhaving a head abutting against the outside surface of said secondplate-like part, said screw engaging said stud.

3. Fastening system according to claim 1, said stud consisting of anexpandable plug.

4. Fastening system according to claim 3, said stud havinglongitudinally extending ribs for compensating tolerances and forsecurity against rotation.

5. Fastening system according to claim 4, said stud consisting of ahollow cylinder, longitudinal ribs on the inside of the wall of saidcylinder for securing said screw member and preventing the same fromdropping out before final tightening and for compensating tolerances.

6. Fastening system according to claim 3, said stud having preparedcracking areas and having a longitudinally extending bore, said borehaving a reduced like part, a screw member anchoring said cylindricalbloc member in the second one of said plate-like parts, a cylindricalstud disposed perpendicular to said axis of said cylindrical blockmember, said stud integrally formed with said cylindrical block member,said stud at least partly embracing said screw member and engaging asecond bore hole in said second part, the diameter of said second holebeing equal to the diameter of said stud, a laterally projectingplate-like flange on one side of said cylindrical block member, saidplate-like flange located on one side of said cylindrical block member,said plate-like flange abutting against said surface of said undersideof said plate-like first part in the area surrounding said first borehole in said underside of said plate-like part and abutting against thesurface of said plate-like second part; said stud consisting of anexpandable plug, said plug having a longitudinal opening, said-openingextending across said cylindrical block member.

8. Fastening system according to claim 3, said stud consisting of anexpandable dowel having a serrated surface.

9. Fastening system according to claim 8, said stud having a cylindricalprojection formed on said cylindrical block member, said cylindricalprojection extending to said second plate-like part, said expandabledowel being disposed in alignment with said cylindrical projection andsaid screw member engaging said dowel and fixing said cylindrical memberon said dowel.

10. Fastening system according to claim 1, and having two cylindricalblock members, one disposed on each side of said second part, the studsof said cylindrical members being positioned in the same opening andbeing connected by a common screw.

11. Fastening system according to claim 1, said laterally projectingflange of said cylindrical block member having a ridge-like projectionthereon, said ridge-like projection being connected to said stud, saidridge-like projection abutting against the surface of said secondplate-like part and constituting reinforcing means at the point ofconnection of said cylindrical block member and said stud.

1. Fastening systsm for connecting two adjacent plate-like parts,particularly for connecting two walls of furniture, said parts beingdisposed perpendicularly to each other, said system comprising acylindrical block member, said member being positioned in a first borehold in the underside of the first one of said plate-like parts, theaxis of said cylindrical block member being perpendicular to the surfaceof said underside of said plate-like first part, a screw memberanchoring said cylindrical block member in the second one of saidplate-like parts, a cylindrical stud disposed perpendicular to said axisof said cylindrical block member, said stud integrally formed with saidcylindrical block member, said stud at least partly embracing said screwmember and engaging a second bore hole in said second part, the diameterof said second bore hole being equal to the diameter of said stud, alaterally projecting platelike flange on one side of said cylindricalblock member, said plate-like flange on one side of said cylindricalblock member, said plate-like flange abutting against said surface ofsaid underside of said plate-like first part in the area surroundingsaid first bore hole in said underside of said plate-like part andabutting against the surfaCe of said plate-like second part. 2.Fastening system according to claim 1, said stud having a lengthsubstantially shorter than the thickness of said second plate-like part,and said screw going through said second plate-like part, said screwhaving a head abutting against the outside surface of said secondplate-like part, said screw engaging said stud.
 3. Fastening systemaccording to claim 1, said stud consisting of an expandable plug. 4.Fastening system according to claim 3, said stud having longitudinallyextending ribs for compensating tolerances and for security againstrotation.
 5. Fastening system according to claim 4, said stud consistingof a hollow cylinder, longitudinal ribs on the inside of the wall ofsaid cylinder for securing said screw member and preventing the samefrom dropping out before final tightening and for compensatingtolerances.
 6. Fastening system according to claim 3, said stud havingprepared cracking areas and having a longitudinally extending bore, saidbore having a reduced diameter in the center area.
 7. Fastening systemfor connecting two adjacent plate-like parts, particularly forconnecting two walls of furniture, said parts being disposedperpendicularly to each other, said system comprising a cylindricalblock member, said member being positioned in a first bore hole in theunderside of the first one of said plate-like parts, the axis of saidcylindrical block member being perpendicular to the surface of saidunderside of plate-like part, a screw member anchoring said cylindricalblock member in the second one of said plate-like parts, a cylindricalstud disposed perpendicular to said axis of said cylindrical blockmember, said stud integrally formed with said cylindrical block member,said stud at least partly embracing said screw member and engaging asecond bore hole in said second part, the diameter of said second holebeing equal to the diameter of said stud, a laterally projectingplate-like flange on one side of said cylindrical block member, saidplate-like flange located on one side of said cylindrical block member,said plate-like flange abutting against said surface of said undersideof said plate-like first part in the area surrounding said first borehole in said underside of said plate-like part and abutting against thesurface of said plate-like second part, said stud consisting of anexpandable plug, said plug having a longitudinal opening, said-openingextending across said cylindrical block member.
 8. Fastening systemaccording to claim 3, said stud consisting of an expandable dowel havinga serrated surface.
 9. Fastening system according to claim 8, said studhaving a cylindrical projection formed on said cylindrical block member,said cylindrical projection extending to said second plate-like part,said expandable dowel being disposed in alignment with said cylindricalprojection and said screw member engaging said dowel and fixing saidcylindrical member on said dowel.
 10. Fastening system according toclaim 1, and having two cylindrical block members, one disposed on eachside of said second part, the studs of said cylindrical members beingpositioned in the same opening and being connected by a common screw.11. Fastening system according to claim 1, said laterally projectingflange of said cylindrical block member having a ridge-like projectionthereon, said ridge-like projection being connected to said stud, saidridge-like projection abutting against the surface of said secondplate-like part and constituting reinforcing means at the point ofconnection of said cylindrical block member and said stud.